Process of refining glyceride oils



Nov. 23. 1937. B. CLAYTON ET AL PROCESS OF REFINING GLYGERIDE OILS Fild Aug. 14, 1953 A TTOAa/VEK Nov.. 23,

PROCESS F BEFINING GLYCEBIDE OILS Clayton,

Sugarland, Tex.,

Walter Benjamin Barnes Kerrlck, Los Angeles, and Henry M.

Stadt, Glendale.

Calif., and Benjamin H.

Thurman, Bronxville, N. Y., sssignors, by di- 1 rect and mesne assignments, to lteilnlng, Inc.,

Reno, Nev., a corporation of Nevada Application sum 14, losa, semi No. 635,130 In England March 25, 1933 23 claims. (cl. lx1- 12) The process relates to the refining oi' glyceride oils. The term "glyceride oils is used in a general sense to include oils of vegetable or animal origin, including the iish oils.

5 The term "raw oil" as used hereinafter is intended to mean a glyceride oil containing impurities. In general the word impur-ities" as used hereinafter is intended to include not only fatty acids (having the general chemical foro mula CnHmCOOH), but also other suspended or dissolved impurities that can be acted upon by a suitable reagent.

It is well known that raw oil may be treated with various alkaline reagents to produce neutralilation. For example. aqueous solutions of caustic soda, sodium carbonate. and other substances are well known to be useful for this purpose and the word reagent when used hereinafter is intended to include all substances which have been so used for the rening of raw oil.

'l'he word "renin'g is intended to mean the process ofneutralization oi raw oils to produce a commercial oil. A Icommercial oil is one that is suillciently free from fatty acids or other impurlties to be readily marketable. Such commercial oils are not necessarily "water white and after being treated as described herein may be subjected to additional treatment to improve their color.

,o In the reiining of raw oils certain reaction products, including. for example, soap stock, are produced, the reaction products being hereinafter called foots". this term at the present time being commonly used in the'art.

It is old in the art to reiine raw oils with reagents to produce ioots and to remove the foots from the oils to produce commercial oils. This is commonly done at the prent time by kettle retning. In kettle refining a batch of raw oil is placed in a suitable container or kettle". this oil being usually at a temperature not greater than that of the room in which the reilning is conducted. Reagent is then added to the kettle. the contents thereof being vigorously agitated during this addition so that the reagent is mixed with the rawoil. During or subsequent to this addition of reagent heat is applied to the kettle, the agitation being continued until the suri'ace oi' the liquid shows a break", the appearance of which is readily detected by the shlled renner.

This break indicates tothe reiiner that reilning is substantially complete. Ii' the oil is now a1- lowed to stand quiescent in the kettle or in some other container to which the oil has beentrans i'erred, the ioots settle out of the oil.

' reagent theoretically necessary to neutralize the free fatty acid. In practice if the reilner merely adds the exact theoretical amount of reagent. he inds that all the impurities are not completely removed or the oil is "under reilne This is due to the fact that while the reagent has a preferential afllnity for the impurities, it will also react with the oil itself to a certain extent causing a refining loss due to reaction-with neutral oil. Considerable retlning loss due to reaction with neutral oil is inevitable in kettle refining and it represents a real monetary loss to the reilner since the foots produced by the action of the reagent on the oil itself are worth less than the oil so destroyed.

It is an object of the invention to provide a process of refining raw oils in which the reining loss is less than that produced by the usual method of kettle rening.

In kettle rening the surface of the oil is ordinarily exposed to the air and during the agitation of the hot oil some oxidation takes place. causing oxidation losses.

It is an object of the invention to provide a process of refining raw oil in which oxidation losses are prevented.

It is at present common practice to rene raw oil in batches; that is, a. body of oil is placed in a container and subjected while in the container or in other containers to which the batch is transi'erred to various successive steps of refining.

It is an object of the invention to provide a continuous process of reiining raw oil in which the oil flows continuously through diierent chambers in each of which one or more oi' the steps of the process is performed.

iBy the use of a continuous process certain advantages are secured, such as, a uniform product, ease of regulation and control, and large capacity.

In the; kettle reiining of oils the refiner is obliged to use relatively lowtemperatures. For example, in the reiining of cottonseed oil it is the .usual practice not vto heat the oil in the kettle much above degrees Fahrenheit (38 degrees centigrade). If the oil is heated much above this temperature, the refined oil is dark in color.

arcane Tests on actual apparatus with which the process described herein was being actually performed indicate that the refining is extremely rapid, the refining being complete in lss than one minute after the reagent is added to the oil.

It is an obiect of the invention to provide a process of refining raw oil in which said renning is very rapidly effected.

Due to the fact that oxidation is prevented and the neutralization is very rapid. it is possible to use temperatures much higher than those previously employed and in fact no injury to the oil results even though the temperature employed is far in excess of that previously considered desirable. In actual tests on cottonseed oil, which if kettle reiined at temperatures above 100 degrees Fahrenheit or 38 degrees centigrade would produce a dark rened oil, it is found possible to use temperatures at least twice those indicated by ordinary kettle refining practice.

It is an object of the invention to provide a process of refining raw oils in which the oil may be subjected to temperatures considerably in excess of those now used in the art.

Contrary to all the teachings of the art, it is possible by the process disclosed herein, using high temperatures, to reduce the color of the refined oil below the color produced in the refined oil by the best standard practice. In other words, for some reason in operating in accordancewiththedisclosureherdmtheuse ofhigh temperatures in place of darkening the refined oil actually tends to decolorime it. This may be due to the very rapid rate at which the refining takes place or to other causes.

It is an object of the invention to provide a process of refining raw oils in which the oil is so treated as to improve the color of the reiined oil over that produced by the processes now in use in the art.

In the kettle rening process the foots are ordinarily separated from the raw oils by gravitational settling. The break relied upon by the renner to indicate complete refining is merely an indication that the particles of foots previously dispersed in the body of the oil have started to agglomerate into masses visible to the eye of the renner. These visible masses are somewhat heavier than the renned oil and if the mixture is allowed to stand in a container they settle tothebottomcarryingsomeentrainedoilwith them.

Manyattemptshavebeenmadeto aeparatethe foots from the renned oil in a centrifuge, whichis a device having a bowl rotating usually about a verticalaxisandintowhichthemixtureof rennedoilandfootslspasaed. Inthecentrifuge. duetothecentrifllaalforceproducedbytherotation of the bowl, the liquid carried tends to stratify. the footsbeing thrown to outside. forminganouterlayeroffootaand Mned oil being forced inwardly toward the axis ofthebowLforminganinnerlayerofrenadoil. Beparateoutletsareprovidedforthetwolayers andwhen thecentriflxeisadjustedtoniitthe characterofliquidfedtheretoreiinedoilsubatantially free from foots is discharged from one outlet and foots substantially free from renned oil are discharged from the other outlet.

Duetothefactthatwhenthebreakoccursin kettlereiiningthefootsaredistributedinthe mixture of reiined oil and foots in the form of visible masses, it has been found dimcult to separate the foots from the oil by centrifugal separation due to the variable nature of the liquid delivered to the centrifuge. This is. of course. due to the fact that whenever a large mass of foots flows into the centrifuge, it fills the centrifuge, displacing the inner layer of rened oil so that foots pass out through the refined oil outlet.

It is an object of the invention to provide a process in which the iened oil and foots are separated by centrifuging.

When operating upon certain oils it is desirable to provide for heating the reagent and oil before combining them. Like most chemical reactions, the action of the reagent on the impurities is rendered more rapid at higher temperatures and due to the manner in which the process is conducted, it is possible to preheat the oil and reagent before mixing them, thus intensifying the reaction after the mixing has taken place. This preheating of the oil and reagent before mixing is contrary to the teachings of the art, the kettle reflner usually starting with a cold mixture of raw oil and reagent and gradually heating the mixture while maintaining a vigorous agitation.

It is an object of the invention to provide a process of treating raw oil in which the oil and reagent may be heated before being mixed.

The actual operation of the process will be better understood if we consider a specific example such as the refining of raw cottonseed oil. Such oil can be conveniently refined in the apparatus shown diagrammatlcally in the annexed drawing.

'Ihe apparatus consists of a proportioning device l, a reagent heater 2, a raw oil heater l, a mixer l, an agglomerator l, and a separator 6.

'Ihe function of the proportioning device is to feed the raw oil and reagent to the other apparatus at constant rates which bear a definite proportion to each other. For example, operating on a raw oil containing by test about 2% of free fatty acids and using a solution of caustic soda in water having a specific gravity of 16 degrees Baume, this caustic soda solution may be fed into the apparatus at about 8% the rate the oil is fed. In general it may be said. the raw oil being fed into the apparatus at a definite rate, that the caustic should be simultaneously fed at a rate somewhat higher than that necessary to theoretically neutralize the impurities in the oil. A

The rates at which the oil and reagent are fed should each be under the control of the operator and any apparatus which will enable the operator to control the proportions of flow will be satisfactory. In the drawing the proportloning device l is shown as consisting of a reagent pump II and a raw oil pump I2. '111e raw oilpump lisdrivenbyashaft Ilfromany convenient source of power, not shown, and the reagent pump Il is driven by a shaft Il oonnectedtotheshaft I8 throughavariablespeed lcarlltheratioofwhichcanbevariedbya 16ml..

The re- .agent-is deliveredby-the reagent pump il toa the raw cil is delivered to a pipe 20. drawlngshows the reagent heater heaterlplacedinsuchaposioil to them, as far as the operation of the procconcerned the reagent and oil might be heatedprior to passing to the proportioning de- As a matter of convenience in operation it better to arrange the apparatus as the drawing.

functiomofthereagenthterhstosupto the reagent and the construction merely a convenient form. As shown reagent heater 2 consists of an outer shell ving reagent from the pipe II and deliverit to a pipe 23. A heating medium such as ll 2| to the space surrounding through a pipe 2l having a valve 2i, eating medium being withdrawn a pipe 2|. A direct flame heater, in agasiiameisusedtoprovidehot comon sgi er s gi d to heat the reagent therein, may. be if desired, or some other form o'f heater maybeused. All that is necessary t the reagent be delivered through the pipe a constant and controlled temperature.

oilheaterllnaybesimilartothere- 2- of an outer shell Il ifinsidewhichisplaced acoil22,thiscoi1 receiving raw oil from the pipe 2l and delivering it to a pipe 23. A heating medium such as hot oil, or steam is delivered to the interior of 'lheformshowninthedrawingconsistsof an outer cylindrical shell or lpipe li secured in gas-tight relationship (by screw threads, for example) in a fitting I2 at one end of. the shell and in'a tting at the other end of the pipe. The reagent inlet pipe 2l` extends through the fitting l2 in gas-.light relationship therewith and into the space inside the shell Ill concentric with the interior thereof.

rodu'which closestheend thereof. 'lheannular spacellbetweentheoutsideofthepipe 22 and rodllandtheinsideoftheshellli iscalledthe mixing space. Mixtures produced in this`space aredeliveredtoapipethreadedintheiltting Il. 'l'he pipe 2l is provided with one or more small holes "through which reagent is ejected from'the interior of the pipe 23 into the mixing space Il. ASince the oil is constantly being forced 7g throinhtbismixingspace, the streamofreagent oil that the proportioning device I feeds cold.

insidewhichisplacedacoil 22,thiscoilre.

which pass upwardly around theA 'lheinrnerendoi'thepipe22isthreadedoria 3 breaks up 'as it leaves .the Vnoie; 41 mm ane dropswhicharecarriedinthebodyofrawoil.

The reagent in each drop is, of course, in contact at its outer surface with the oil and the reagent acts on the oil, neutralizing the im- 5 purities therein. By breaking up the reagent into a multiplicity oi' small drops the total interfacial contact between the outer surface of these drops and the oil is very large and rapid refining of the oil is therefore accomplished regardless l0 of the temperature of the oil and reagent. It may, however, be said that the reaction is appatently quicker with hot oil and reagent than with cold.

By uniformly dispersing small drops of reagent l5 in oil the reagent is brought into intimate contact with the oil without the concentration of the larger masses of reagent inherent to kettle reilning in which the oil is run into the kettle in a stream and tends to settle in the bottom oi' 20 the kettle until picked up and broken into small by the agitator. 'I'he drops of reagent also have an initial movement as they leave the fe. holes l1 and the oil itself is in motion so that each drop of .reagent moves about in the body, of the oil and the oil at the interfacial surface of each drop is constantly'phanging. As a result, the rening is not only rapid and complete, but refining losses are greatly reduced, the reagent being able to quickly find impurities upon which it can act so that the relatively slow action of reagent on the oil itself is very small. By using the type of mixer shown, the reilner is able to completely reflne the oil using only slightly more reagent than would be theoretically necessary and with very low refining losses.

While the speciic form of mixer 4 shown in the drawing and described herein has certain marked advantages as previously pointed out, if these advantages are not desired. the functions of the mixer may be performed by any form of mechanical mixer through which the oil and reagent are passed and in which the reagent is mechanically broken up into small drops.

. While the holes I1 are preferably distributed` 45 uniformly in a spiral path about the pipe 23, this is probably not essential, a single hole being sumcient provided it is so placed as to produce a uniform dispersion of the reagent in the raw oil.

The purpose of heating the raw oil prior to the introduction of the caustic therein is to promote the reaction between the reagent and the impurities and to reduce the viscosity of the oil so that the drops of reagent produced in the mixer l have a greater freedom of movement in the body of the oil during the reaction and agglomeration periods and the centrifuging is facilitated. Itis a well known fact-that the viscosity of glyceride oils is reduced by heating and the degree of heat used is dependent upon the vis- 00 'cosity-temperature characteristics of the oil. 'I'he oil should be suillciently hot when delivered to the centrifuge 6 to permit of efilcient separa tion. -f l In some cases it may be convenient to dispense with the reagent heater 2 and connect the pipe i! directly to the pipe 23. Since the reagent is finely divided in the mixer l and introduced into the body of the oil, in fine drops'. the conditions Kfor heat transfer are veryv good and the reagent 7i) ofreagentorfootstocoalesoeintolargemanes toassistincentrifuging.towhichtheoilislater subiected.

'I'he agglomerator l shown in the drawing con- '5 sistsofanoutershellllinwhichisplaceda helical coil I! of pipe, one end of this coil l! being connected to the pipe 4I and the other end being connected to a pipe I8. In refining certain oils it is desirable t9 control the tempera- 10 ture of the mixture while it is in the agglomerator.

A pipe Il having a valve I4 delivers liquid into the space inside the shell Il around the coil Il, this liquid being withdrawn through a pipe il.

The liquid delivered through the pipe Il may l5 be either a heating or cooling medium, depending upon the temperature of the oil flowing through the pipe Il. In some cases it may be unnecessary to yuse either a heating or cooling medium on the coil Il, in which case the interior of the shell may be lined or filled with heat insulating material such as' loose asbestos fibers.

In the refining of cottonseed oil having from 2% to 3% of free fatty acid excellent results are obtained if the oil is pumped through the apparatus at the rate of about sixteen pounds per minute and the agglomerator consists of from 250 to 500 feet of pipe one-half to three-fourths inch inside diameter.

If the mixing space 4l is suillciently long, neutralization is almost wholly completed when the oil enters the coil l2. This is not important since if it is not complete it proceeds to completion in the upper part of the coil 52. In any event the neutralization is completed either before the oil enters the coil i2 or soon thereafter.

As soon as the neutralization is complete, the drops of reagent have been converted into small particles of foots, which in the rening of cottonseed oil appear as loose` masses of microscopic 4o size. Some of these masses are so small that their separation from the oil is dimcult.

The agglomerator tends to coalesce these masses of foots into l er masses which is accomplished by allowing the oil to flow with only a mild agitation through the coil l2. By making this coil of pipe bent into a continuous helix or spiral this mild agitation is produced due to the uniform and gradual change in direction of the coil. In their travel the larger masses of foots capture and agglomerate with the smaller, producing a mixture in which the-foots appear as masses which are largerthanthemassesoriginallyproducedduring neutralisation, but which due to the constant motion of the oil have not been allowed to stratify or agglomerate into large masses like those seen by the kettle renner after the break.

. It is highly desirable toprevent agitation or turbulence in the agglomerator such as would tendtobreakupthesmallmassesoffootspro- 00 duced by neutralisation. and it is also desirable to keep tbe oil in motion to prevent the foots from stratifying into masses ofsuch sise that they would interfere with centrifugal separation.

Ihe mixture of oil andfoots delivered to the espipellshouldbeinconditiontobeeasilycentrifuged. If the oil is naturally viscous at atmospheric temperatures. it should be hot enough toreduceitsviscosity,andthefootsshouldbe uniformlydistributedintheoilinmanesof 7o fairly uniform sise, which sise s hould be auch that the mass separate readily from the oil during the centrifuging operation.

'I'he'functionofthecentrifugelisto separate Vthef ootsfromtheoilarrddeliverthem 15 apipell'tosuitablest'agenotahowmtheoil being delivered through a ill .I to suitable storage, not shown. Oentrifuges for performing this operation are readily available, containing usually a-bowi mounted on a vertical shaft which isrotatedatahighspcedbyanelectricmotor. s Since such separators are old and well known, their construction need not be described herein.

It is understood that thermometers. gauges, and other indicating devices, not shown, are supplied to enable the operator to fully determine 1o at all times the conditions in the various piec of apparatus, and valves and other control devices, not shown, are supplied to yenable the operator to control said conditions.

.The operation of the process will be better 15 understood by considering it applied to the reilningofacottonseedoilcontainingabout2% of free fatty acid. Ihis oil was pumped through the apparatus at the rate of about sixteen pounds a minute. A reagent consisting of a solution of 2o caustic soda in water was used, this reagent having a specific gravity of sixteen degrees Baum. Reagent was pumped into the mixer at the rate of about one and one-fourth pounds per minute. 'Ihe coil!! consisted of about 250 feet of three- 25 fourths inch (inside diameter) pipe and the pumps Ii and i2 built up a pressure of about 80 pounds per square inch.- The oil and caustic were heated to about F. before being delivered to the mixer l. Experiments indicate that con- 30 siderably higher temperatures might be used to advantage. Operating on this particular oil it was proved unnecessary to supply heat to the agglomerator I although centrifuging was facilitated if some heat was applied to the coil l2 so 35 that the oil in the pipe Il hada temperature of about P. i

The oil delivered through the pipe 02 was a good commercial oil and in spite of the high ternperatures used had a better color and clarity than v40 v the oil produced by refining the same raw oil by v By the employment of the term color setting" temperature we mean to define and embrace a '55 temperature ranging from not substantially leas than 100' P. to not substantially more than 200 1'.. for the average oils, and which is suiilciently high to set the color in the conventional batch process, as above describai, as distinguished from o0 the presentprocessinwhichsuchactionisminimiaed by heating small quantities of the oil or b! permitting the heated oil to remain in contact with the saponifying reagent for such a brief time astominimisesuchaction.' g5

We claimas our invention:

l. In the purification of glyceride oils containingfreefattyacidwhichincludesmixingameasured quantity of oil with a measured quantity of a saponifying reagent for a brief period to 7o formsoapstock.andpasaingtheresultingmix turetoacentrifugal mtorfortheprompt separationofthereilnedoilfromthesoapstock.' theimprovementwhichcomprisespre-heatingat leastoneoftheadmixedmaterialsbeforead-u mixturewiththeothertoatemperamrswhich willcausethemixturetobeatanemulsion meme@ as canned in claim 1 in which the oil is pre-heated, before admixture with the Asaponifying reagent, to said "emulsion breaking or opposing" texiiperature.l

3; 'Ihe process as defined in claim i in which thetemperatureofsaidmixtureisinexcessof 100' Il'.

4.'.lheprocessasdeilnedinciaimi inwhich the temperature of said mixture is in excess of 100 F. and not substantially more than 200 1|'.

5. Theprocessasdeflnedinclaimlinwhich the temperature of saidmixture is between 100 1". and 160 r'.

6..'Iheprocessasdeiinedinclaim1inwhich the mixing of said materials is performed while excluding substantial quantities of air.

7. Theprocessasdeflnedinclaimlinwhich the mixture is passed to the centrifugal separator under super-atmospheric pressure.

8. The processas defined in claim 1 inl which `thematerialsarepumpedtothemixingaoneanii the mixture pumped to the centrifugal separator.

'9. 'Ihe process as defined in claim 1 in which the oil is pre-heated during stream now.

10. The processus defined in claim 1 in which the process is carried out in a single operation and during the continuous movement of the materials.

11. In the purincation of glyceride oils containing free fatty acid which includesmixing a measured quantity of oil with a measured quantity of a saponifying reagent for a brief period to produce an emulsion in which the reagent is distributed as the dispersed phase of the mixture;

passing the reauung mixture of soap stock and oil to a centrifugal separator for the prompt separation ofthe rened oil from the soap stock, the improvement which comprises breaking said emulmcn by pre-heating at least .one of theadmixed materials before admixture with the other toatemperaturewhichwilicamethemixtureto be at an emulsion breaking` temperature sutilcient tooondition the mixture for the step of ccntrifugally separating the soap stock from the rened oil.

12. In the purification of glyceride oils containing free fatty acid and color impurities, a 1

process comprising mixing a measured quantity of oil with a measured. quantity of a saponifying reagent for a brief period and promptly centrifugally separating the refined oil from the resulting soap. stock, the improvement which comprises pre-heating the oil to an emulsion breaking or opposing and color setting e and limiting the time of contact of the oil with the saponifying reagent to such a brief period las to minimize saponiiication and setting of the color of the oil. l

13. 'Ihe process as deilned in claim 12 in which the saponii'ying reagent is present in an amount Ainexcessofthatnequiredtone'utralisethefree fatty acid and in which substantially complete neutralimtion is effected during mixing.

14. A process of purifying glyceride oils containing free fatty acid and color impurities which comprises pre-heating the oil to an emulsion breaking or opposing" and color setting temperature while minimizing the setting ofsaid color by rapidly heating small quantities of the oilforalimitedduraticncdtlmamixingthethm pre-heatedoilwithasaponifyingrelgmttoeffeet, rapid neutralisation of the free fatty acid andtheformationofsoapstock.passingthethus conditioned mixture to a centrifugal separator :undseparatingthesoap stock from thereiined i5. A process of purifying glyceride oils containing free fatty acid and color impurities which comprises rapidly heatingsmail quantities of the oil to a color setting temperature, mixingthethusheatedoilandasaponifyingreagent to form a-mixture of -oii and soap stock and promptlyseparatingsaidsoapstockfromsaid oil before substantial settingof thecolor has occurred.

16. Theprocessasdennedinclaimwinwhich the heating and mixing is carried out during cmtinuous now of the oil.

17. In the purification of glyceride oils containing free fatty acid and color impurities, a quick process comprising mixing small quantities of oil and a saponii'ying reagent for a brief period to form soap stock. heating the oil to a temperature which will cause the resulting mixture to be at an emulsion breaking or opposing" temperature in excess of 1"., prior to mixing the same with said saponifying reagent, whereby to rapidly condition the mixture of oil and soap stock Ythe materials from the point of contact to the point of introduction to the centrifugal separator are mainained in a closed system and `under suiilcient movement to prevent stratification of the soap stock and the oil.

19. In the purification of glyceride oils ccntalning free fatty acid and color impurities. a quick continuous process comprising pumping small metered quantities of oil and a saponifying reagent to a mixing zone, heating the oil before admixture with the saponifying reagent to a v temperature which will cause the resulting mixture to be at an emulsion breaking or opposing temperature, subjecting the materials to mechanical agitation of such brief duration and while excluding air to effect rapid neutralization of` the free fatty acid, and to condition the mixture for prompt separation of the resulting soap stock from the oil, advancing the mixture under pump pressure to a centrifugal separator while providing sumcient time for the oating soap stock particles contained in the conditioned mixture to combine with color impurities. and promptly sub- .iecting the conditioned mixture to centrifugal separation.

20. In thevpurication of glyceride oils con- 00 taining free fatty acid and color impurities, a quick continuous process comprising pumping small metered quantities of oil and a saponifying reagent as separate continuously advancing streams to a mixing sone, heating the advancing stream of oil to a temperature which will cause the resulting mixture to be at an emulsion breaking or opposing temperature substantially in emcess of 100 F., stream of saponifying reagentinan amountinexcessofthat requiredto eifecttheneutraliaationofthetreefattyaddwith midoilinsaidaoneforabriefperiodtoeifect quick and.substantially complete neutralization ofthefreefattyacid insaidoil andtosubstantially immediately produce a mixture containing softenedlooaefloatingparticlesofsoapstock conment as to prevent substantial stratiiication of the soap stock and provide for said agglomeration with the color impurities, and promptly subjecting the thus conditioned mixture to centrifugal separation to separate thefsoap stock and color impurities combined therewith from the purined oil.

3l. In the purification of glyceride oils containing free fatty acid and color impurities, a quick continuous process comprising pumping small metered quantities of oil and a saponifying reagent'as separate continuously advancing streams` to produce a mixture containing loose floating: particles of soap stock conditioned for the agglomeration of color impurities therewith, advancingthemixture throughanelongated conduit under super-atmospheric pressure maintained by said pumping and in a state of movement such as to prevent substantial stratification of the soap stock while providing for the aggiomeration of the soap stock particles and the comhinaon therewith of color impurities, introducing the thus conditioned mixture promptly toacentrihualseparatorfortheaeparationof the agglomerated soap stock and combined color impurities from the purified oil and adJusting the temperature of the mixture passing through the conduit to facilitate centrifugal separation.

22. In the purification of glyceride oils containing free fatty acid. a process comprising mixing measured quantities of oil and a saponifying reagent for a brief period to form soap stock, heating the oil to a temperature which will cause the resulting mixture to be at an "emulsion breaking or opposing temperature in excess of 100 I'. prior to mixing the same with said saponifying reagent whereby to rapidly condition the mixture of oil and soap stock for the separation of the soap stock from the oil, maintaining the mixture under such agitation as to provide for agglomeration of the soap stock particles and separating the thus agglomerated soap stock particles from the refined oil.

23. In the puriiication of glyceride oils containing free fatty acid, a quick continuous process comprising mixing measured quantities of oil and a saponifying reagent for a brief period to effect reaction with the free fatty acid contained in the oil and to form soap stock, thereafter promptly separating the purified oil from the soap stock, the process being characterized by limiting the time of contact of the reagent and oil to such a brief period as to minimize reactions with the puriiled oil and by preheating the oil before admlxture with the saponifying reagent to a temperature such that the mixture of soap stock and oil has an emulsion breaking or opposing" temperature at the time of `undergoing separation whereby to condition the mixture furthe separation of the soap stock from the oil.

' BENJAMIN CLAYTON.

WALTER BARNES KERRICK. HENRY M. STADI'. I BENJAMIN H. THURMAN. 

